Overview

Brief Summary

Abies is a genus of between 48-55 species of evergreen conifers in the family Pinaceae, generally known as firs. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range. Nine species are native to North America. Firs are most closely related to the cedars (Cedrus). Douglas-firs are not true firs, but are instead of the genus Pseudotsuga.

All are trees, reaching heights of 10-80 m (30-260 ft) tall with trunk diameters of 0.5-4 m (2-12 ft) when mature. Firs can be distinguished from other members of the pine family by their needle-like leaves, attached to the twig by a base that resembles a small suction cup; and by erect, cylindrical cones 5-25 cm (2-10 in) long that disintegrate at maturity to release the winged seeds. Identification of the species is based on the size and arrangement of the leaves, the size and shape of the cones, and whether the bract scales of the cones are long and exserted, or short and hidden inside the cone.

Abies wood is lightweight and decays quickly, so the primary timber uses are for pulpwood and construction (plywood). Some species have bark or leaves produce oleoresins that are used to make turpentine, varnishes, and Canada balsam (used as a slide fixative) and in the manufacture of medicinal compounds. The resin is reported to have numerous medical uses, including as an antiseptic, diuretic, expectorant, and vasoconstrictor. Various species have found widespread commercial success as Christmas trees, as celebrated in Hans Christian Anderson's famous fairy tale, The Little Fir Tree (recited in this YouTube clip). A few species are highly prized ornamentals.

Some Abies species are widespread in boreal forests around the globe; in lower latitudes, they are generally found at high elevations. A. sibirica forms vast forests through northeastern Russia and Siberia and Turkestan. A. alba, silver fir, is an important timber tree in southern and central Europe. A. balsam is important in northeastern North America, where it forms large single-species stands or is one of the dominant species in several boreal forest types. The North American silver firs (A. amarabilis and A. alba) are important in the coastal rain forests of the Pacific Northwest. A. concolor (white fir), A. lasiocarpa (alpine fir), and A. grandis (grand fir) are also extensive distributed in the Pacific and Mountain-Desert regions.

Firs are moderately important to wildlife. The young trees are used as cover for mammals and nesting sites for birds. Deer and moose browse the leaves, sometimes extensively in winter. At least 8 species of songbirds and several mammal species eat the winged seeds.

They are large trees, reaching heights of 10–80 m (33–262 ft) tall and trunk diameters of 0.5–4 m (1 ft 8 in–13 ft 1 in) when mature. Firs can be distinguished from other members of the pine family by the unique attachment of their needle-like leaves and by their different cones.

Identification of the different species is based on the size and arrangement of the leaves, the size and shape of the cones, and whether the bract scales of the cones are long and exserted, or short and hidden inside the cone.

Firs can be distinguished from other members of the pine family by the unique attachment of their needle-like leaves to the twig by a base that resembles a small suction cup.

The leaves are significantly flattened, sometimes even looking like they are pressed, as in A. sibirica.

The leaves have two whitish strips on the bottom, each of which is formed by wax-covered stomatal bands. The upper surface of the leaves usually is uniformly green and shiny, without stomata or only with few at their tips, visible as whitish spots. Some of the species however have the upper surface of leaves dull, gray-green, bluish-gray to silvery, coated by wax with variable number of stomatal bands, and not always continuous. An example species with shiny green leaves is A. alba, and an example species with dull waxy leaves is A. concolor.

Wood of most firs is considered unsuitable for general timber use, and is often used as pulp or for the manufacture of plywood and rough timber. Because this genus has no insect or decay resistance qualities after logging, it is generally recommended for construction purposes as indoor use only (e.g. indoor drywall on framing). This wood left outside cannot be expected to last more than 12 to 18 months, depending on the type of climate it is exposed to. It is commonly referred to by several different names, including North American timber, SPF (spruce, pine, fir) and whitewood.

Nordmann fir, noble fir, Fraser fir and balsam fir are popular Christmas trees, generally considered to be the best for this purpose, with aromatic foliage that does not shed many needles on drying out. Many are also decorative garden trees, notably Korean fir and Fraser fir, which produce brightly coloured cones even when very young, still only 1–2 m (3.3–6.6 ft) tall. Other firs can grow anywhere between 30 and 236 feet (9.1 and 71.9 m) tall. Fir Tree Appreciation Day is June 18.